I swapped from sky broadband, to BT broadband 2 years ago. What a massive mistake that was!
I was getting very slow speeds through Sky, because BT throttle back speeds on the lines to suit themselves.
after a couple of days of having BT, I had to have an engineer come out because my connection started dropping out and my speeds were diving well below the 50Mbps that they guaranteed.
Fast forward 2 years and here we are, just 2 weeks after getting the fault fixed, but still getting slow speeds.
To add insult to injury, they just offered me £20 compensation for 18 months disrupted service and slow speeds!
AVOID USING BT!!! Be warned.......